Dietary Nicotine Associated with Lower Parkinson’s Disease Risk

A study funded by the NIEHS found that people who consumed nicotine-containing vegetables, especially peppers, had a lower risk of developing Parkinson’s disease. Previous studies have consistently shown an association between tobacco product use and a lower risk of Parkinson’s disease, and the new study contributes additional evidence that nicotine may be responsible for tobacco’s potentially protective effect.

The researchers studied 490 people with newly diagnosed Parkinson’s disease and 644 people who were neurologically normal. They compared the consumption of peppers, tomatoes, and potatoes, which all contain nicotine and are members of the same botanical family (Solanaceae) as tobacco. Parkinson’s disease risk was reduced with increased frequency of consumption of these nicotine-containing vegetables (relative risk [RR] = 0.81, 95 percent confidence interval [CI] = 0.65-1.01 per time per day), but not for other vegetables (RR = 1.00, 95 percent CI = 0.92-1.10). They observed an inverse association for peppers specifically (ptrend = 0.005), and noted that the trend toward a lower Parkinson’s disease risk was stronger when they examined edible Solanaceae by nicotine concentration (ptrend = 0.004) or focused on men and women who never used tobacco regularly. The researchers caution that their findings need to be confirmed and extended through additional studies to better understand the relationship between Solanaceae phytochemicals and Parkinson’s disease and whether possible dietary or pharmaceutical interventions could lessen the risk.